Packaging container and process of packaging materials



PACKAGING CONTAINER AND PROCESS OF PACKAGING MATERIALS Frank Herrmann,Lahr, Schwarzwald, Germany, assignor to Kunststolfwerk Lahr G.m.b.H.,Lahr, Dinglingen, Schwarzwald, Germany No Drawing. Filed Aug. 27, 1959,Ser. No. 836,319

Claims priority, application Germany Sept. 4, 1958 7 Claims. (Cl.206-84) The present invention relates to a packaging container forfilling up and packaging solid, meltable products which are sticky whenmolten, and more particularly, to such a packaging container made frompolypropylene and to a process of filling up and packaging suchmaterials into said containers.

In several technical fields it is necessary to pour hot liquidmaterials, for instance bitumen or high melting point paratfins, forstorage or shipping purposes into containers. Up to the present, suchmaterials have generally been put into sheet metal containers. Thesesheet metal containers are stable. However, it is difficult to get thematerials out of such containers again, as they adhere to the sheetmetal even in the heated and molten state. For this reason, jute sacksimpregnated with alginates and calcium chloride have also been used forpackaging such materials. Packaging containers of this latter kind are,however, relatively expensive. Attempts have also been made to useplastics and paper for packaging such materials. However, many of thesepackaging materials are practically useless for this purpose becausethey are too sensitive to heat. On the other hand, the hot liquidmaterials which are to be packed are inclined to adhere to thoseplastics which are sufiiciently heat-resistant.

Therefore, it is one object of the present invention to provide apackaging container for filling up and packaging solid, meltableproducts which are sticky when molten and which are to be packaged whenhot, which container may readily be removed from the packaged material.

Another object of the present invention is to provide a process offilling up and packaging solid, meltable products which are sticky whenmolten and which are to be packaged when hot. Other objects of thepresent invention and advantageous features thereof will become apparentas the description proceeds.

It has been found that polypropylene is very well suited for packagingcontainers for materials which are to be packaged while hot.Unexpectedly, polypropylene does not consolidate with hot bitumen orparaifins and can be stripped from the cooled bitumen or parafiinwithout difficulty which fact is all the more surprising as polyethylenecannot be used for these purposes. For the pur- 1 poses of the presentinvention, packaging containers, for

instance bags of a suitable material such as paper bags, may be used,the inner surface of which is lined with polypropylene foils.

In the process according to the present invention the solid, meltableproducts which are sticky when hot and molten are filled up and packagedin containers of polypropylene, preferably polypropylene bags in the hotand molten state.

?atented Dec. 33, 1960 The packaging of the hot materials according tothe present invention is preferably carried out in such manner thatduring the filling process the preformed container of polypropylene issupported in a correspondingly shaped rigid container, for example ofmetal sheet. If desired, a frame of a suitable material, for instancemetal sheet or plastic, may be placed into the opening of the bag-likecontainer in order to suspend it, reinforce its upper edge and keep itopen while pouring the hot and liquid material to be packaged. After thehot material has been poured into the polypropylene container and hascooled, the frame-like reinforcement is removed and the filledpolypropylene container is removed from the supporting container ofmetal sheet. When using propylene films or foils of wall thickness offrom 0.03 to 0.05 mm. it is possible to package bitumen in this way inamounts of 30 kg. in weight for instance without difliculty.

According to another embodiment of this invention the polypropylenepackaging containers are of various colours so as to distinguishdifferent qualities of the packed material.

What I claim is:

1. Packaging containers for packaging solid, meltable products which aresticky when hot and molten, in the hot and molten state, said containersconsisting of polypropylene.

2. Packaging containers for packaging solid, meltable products which aresticky when hot and molten, in the hot and molten state, said containersconsisting of a polypropylene bag.

3. Process of filling up and packaging solid, meltable products whichare sticky when hot and molten, the steps which comprise melting saidproducts, pouring them into bags of polypropylene foils placed into aremovable rigid correspondingly shaped container, cooling down theproducts, and removing the rigid container.

4. Process of filling up and packaging solid, meltable products whichare sticky when hot and molten, the steps which comprise melting saidproducts, pouring them into bags of polypropylene foils placed into aremovable rigid correspondingly shaped container and suspended andreinforced at the opening by a rigid frame placed removably in theopening of the bag, cooling down said products, and removing the rigidframe and container.

5. A package of a solid meltable product which is sticky when hot andmolten comprising said product and a container for said product, saidcontainer consisting of polypropylene foils.

6. A package of bitumen comprising bitumen and a container for thebitumen, said container consisting of polypropylene foils.

7. A package of high melting point parafiine comprising high meltingpoint paraffine and a container for said high melting point parafiine,said container consisting of polypropylene foils.

References Cited in the file of this patent UNITED STATES PATENTS2,348,622 Heilm-an May 9, 1944 2,804,205 Barton et a1 Aug. 27, 19572,834,768 Friedlander May 13, 1958 2,840,551 Field et al. June 24, 1958

5. A PACKAGE OF A SOLID METABLE PRODUCT WHICH STICKY WHEN HOT AND MOLTENCOMPRISING SAID PRODUCT AND A CONTAINER FOR SAID PRODUCT, SAID CONTAINERCONSISTING OF POLYPROPYLENE FOILS.